Re: binary data

postgresql's large object functions can be used to store and retrieve binary
data.

http://www.ca.postgresql.org/devel-corner/docs/postgres/lo-interfaces.html

here is some sample code:

inv_oid = lo_creat(dbconn, INV_READ | INV_WRITE);
if (inv_oid == InvalidOid) {
fprintf (stderr, "lo_creat failed: %s\n", PQerrorMessage(dbconn));
return (1);
}

res = PQexec(dbconn, "BEGIN WORK");
if (!res || PQresultStatus(res) != PGRES_COMMAND_OK) {
fprintf(stderr, "PQexe(\"BEGIN WORK\") failed: %s\n",
PQresultErrorMessage(res));
return (1);
}
PQclear(res);

obj_fd = lo_open(dbconn, inv_oid, INV_READ | INV_WRITE);
if (obj_fd == -1) {
fprintf (stderr, "lo_open failed: %s\n", PQerrorMessage(dbconn));
return (1);
}

ret = lo_write (dbconn, obj_fd, buf, buflen);
if (ret == -1) {
fprintf (stderr, "lo_write failed: %s\n", PQerrorMessage(dbconn));
return (1);
}

ret = lo_lseek(dbconn, obj_fd, 0, SEEK_SET);
if (ret == -1) {
fprintf (stderr, "lo_seek failed: %s\n", PQerrorMessage(dbconn));
return (1);
}

ret = lo_read (dbconn, obj_fd, buf, buflen);
if (ret == -1) {
fprintf (stderr, "lo_read failed: %s\n", PQerrorMessage(dbconn));
return (1);
}

lo_close(dbconn, obj_fd);

res = PQexec(dbconn, "COMMIT");
PQclear(res);